Stereophotogrammetric analysis of nasolabial morphology among Asian Malays: influence of age and sex

Quantitative Assessment of Lip Morphology in Patients With and Without Cleft Lip and Palate Using 3-Dimensional Stereophotogrammetry

This study aimed to assess and quantify the morphologic characteristics of the lips and the lower third of the face in cleft and noncleft patients, utilizing three-dimensional (3D) stereophotogrammetry. Sixty patients were included in the study, comprising 30 unilateral cleft lip and palate patients (G1, 24 female, 6 male; aged 20 to 60 y, mean age 44.0±12.0 y) and 30 noncleft patients (G2, 23 female, 7 male; aged 20 to 59 y, mean age 43.5±12.0 y). Anthropometric landmarks were identified on the facial surface. Three-dimensional stereophotogrammetry was employed to capture images. Statistical analysis was conducted to compare the groups, with a significance level set at 0.05. The comparative analysis revealed statistically significant differences in 5 linear and 6 angular measurements. Linear measurements such as philtrum width, upper and lower cutaneous lip height, mandibular ramus length, and midfacial depth exhibited significant differences between cleft and noncleft patients. Similarly, angular measurements, including upper lip angle, Cupid's bow angle, lower/medium face convexity, lip seal, nasolabial angle, and left gonial angle, displayed statistically significant disparities. These findings underscore the ongoing surgical challenges in the comprehensive rehabilitation of patients with clefts, highlighting the critical need for continued advancements in treatment strategies.

Nasal Morphology in a Young Adult Middle-Eastern Population: A Stereophotogrammetric Analysis

AIM

This study aimed to describe gender-specific three-dimensional morphology of the soft-tissue nose in Lebanese young adults and to explore the associations between nasal morphology with age and body mass index (BMI).

MATERIALS AND METHODS

Three-dimensional photographs were captured for 176 young healthy Lebanese adults (75 males and 101 females) aged 18.1-37.68 years. Linear and angular nasal measurements were computed and compared between genders, in addition to other established norms. Associations with age and BMI were also assessed.

RESULTS

All linear measurements were greater in males than in females, and only the nasolabial angle was significantly larger in females by 2.97 degrees on average. Most of the measurements were found to be larger than the Caucasian norms. A few significant correlations were found between the measurements and age or BMI.

CONCLUSION

This study is the first to present the sex-specific norms for nasal morphology in the Lebanese population and highlights the presence of gender dimorphism in the majority of measurements. Additional studies are needed to validate our data and expand the associations with age and BMI.

CLINICAL SIGNIFICANCE

The data offered in this study could help enhance the accuracy of facial reconstructive surgery and aid in personalized treatment planning for both medical and cosmetic nasal interventions. How to cite this article: Saadeh M, Shamseddine L, Fayyad-Kazan H, et al. Nasal Morphology in a Young Adult Middle-Eastern Population: A Stereophotogrammetric Analysis. J Contemp Dent Pract 2024;25(3):199-206.

A comprehensive evaluation of the phenotype-first and data-driven approaches in analyzing facial morphological traits

The phenotype-first approach (PFA) and data-driven approach (DDA) have both greatly facilitated anthropological studies and the mapping of trait-associated genes. However, the pros and cons of the two approaches are poorly understood. Here, we systematically evaluated the two approaches and analyzed 14,838 facial traits in 2,379 Han Chinese individuals. Interestingly, the PFA explained more facial variation than the DDA in the top 100 and 1,000 except in the top 10 phenotypes. Accordingly, the ratio of heterogeneous traits extracted from the PFA was much greater, while more homogenous traits were found using the DDA for different sex, age, and BMI groups. Notably, our results demonstrated that the sex factor accounted for 30% of phenotypic variation in all traits extracted. Furthermore, we linked DDA phenotypes to PFA phenotypes with explicit biological explanations. These findings provide new insights into the analysis of multidimensional phenotypes and expand the understanding of phenotyping approaches.

Facial Analysis of Patients with Unilateral or Bilateral Cleft Lip and Palate Using 3D Stereophotogrammetry

OBJECTIVES

To evaluate the quantitative values of linear and angular facial anthropometrics in patients with unilateral cleft lip and palate (UCLP) and compare them with those of patients with bilateral cleft lip and palate (BCLP) using three-dimensional (3D) facial imaging.

DESIGN

Retrospective, observational, and cross-sectional study.

SETTING

Hospital for Rehabilitation of Craniofacial Anomalies/USP (HRAC/USP).

PATIENTS/ PARTICIPANTS

In total, 61 non-syndromic patients with CLP who underwent multidisciplinary treatment and rehabilitated with a prosthesis were enrolled and divided into those with UCLP (G1; n = 31) and those with BCLP (G2; n = 30).

INTERVENTION

Facial images were captured using a 3D camera after landmarks were marked on each patient's face. The software evaluated linear and angular parameters. Statistical tests were applied. Significance was determined as P < 0.05.

MAIN OUTCOME MEASUREMENTS

Overall, 22 linear and 13 angular measurements were evaluated.

RESULTS

The nasal length (P = 0.08), middle third of the face (P = 0.06), base nose width (P < 0.001), nasal root width (P < 0.001), nasal tip angle (P = 0.018), philtrum width (P < 0.001), lower face width (P = 0.039) and midfacial depth (P = 0.040) were significantly higher in G2; the upper cutaneous lip height was significantly higher in G1. Sexual dimorphism was observed except for linear measurements (linear distance between the labiale superius and labiale inferius landmarks, nasal root width, and upper cutaneous lip length) and angular measurements.

CONCLUSIONS

G2 had a greater length and width of nose and nasal root, nasal tip angle, philtrum width, and lower face width, midfacial depth, and midface third than G1. These findings also revealed the presence of sexual dimorphism.

Head and face anthropometric study for respirators in the multi-ethnic Asian population of Malaysia

Background

Existing anthropometric studies for respirator designs are based on the head and facial dimensions of Americans and Chinese nationals, with no studies for multi-ethnic countries like Malaysia. This study aimed to create head and facial morphological database for Malaysia, specifically to identify morphological differences between genders, ethnicities, and birthplaces, as well as predictors of the dimensions.

Design

A cross-sectional study.

Setting

Malaysia.

Participants

A nation-wide cross-sectional study using a complex survey design with two stage-stratified random sampling was conducted among 3,324 participants, aged 18 years and above who were also participants of the National Health and Morbidity Survey 2020.

Primary and secondary outcomes

The study collected data on sociodemographic, measurement of Body Mass Index (BMI) and 10 head and facial dimensions (3 dimensions were measured using direct measurement, and 7 others using Digimizer software for 2-dimension images). Linear regression was performed to determine the association between gender, ethnicity, birthplace, age and BMI and the dimensions.

Results

There were significant differences in all the dimensions between sex, birthplace and ethnicity (p < 0.005). Further analysis using linear regression showed sex, ethnicity, birthplace, age and BMI were significant predictors of the dimensions. In comparison to studies from the United States and China, our study population had a wider interpupillary distance and nose breadth for both male and female participants, but smaller bigonial breadth and smaller minimal frontal breadth.

Conclusion

These findings could assist in the design and sizing of respirators that will fit Malaysians and possibly other Southeast Asian population.

Stereophotogrammetric analysis of labial morphology in a young adult Middle-Eastern population

INTRODUCTION

The majority of previous research delineating the morphological characteristics of the orolabial region has been on Caucasian populations, with very minor research on Mediterranean populations, and none on the Lebanese population.

AIM

The primary aim was to collect information on the gender-specific 3D morphology of the mouth and lips in young Middle Eastern adults. The secondary aim was to explore the presence of associations between orolabial morphology and age and body mass index (BMI), and to assess correlations between linear orolabial dimensions and area/volume measures.

METHODS

The study used non-invasive stereophotogrammetry to collect information on gender-specific 3D labial morphology (linear distances, areas, and volumes) for 122 adult Lebanese subjects, aged 18-30 years (47 males, 75 females). Associations between labial morphology and age and body mass index were assessed, in addition to correlations between linear orolabial dimensions and area/volume measures.

RESULTS

All linear, angular, area, and volume lip measurements displayed significant variability. Both lip area and volume were smaller in the upper than in the lower lip. Eighteen out of the 20 linear measurements were significantly larger in males. The ratio, area, and volume measurements mostly displayed no statistically significant gender dimorphism.

CONCLUSIONS

Alongside presenting the first documented report on anthropometric labial measurements of a young Lebanese adult population, this research highlights the presence of gender dimorphism in linear and angular measurements, but not in area and volume measurements, and a strong association between certain linear labial measurements and lip area and volume. In addition, it presents pilot data on the association between labial anthropometry and body mass index.

Anthropometric Study of Three-Dimensional Facial Morphology in Malay Adults

OBJECTIVES

To establish the three-dimensional (3D) facial soft tissue morphology of adult Malaysian subjects of the Malay ethnic group; and to determine the morphological differences between the genders, using a non-invasive stereo-photogrammetry 3D camera.

MATERIAL AND METHODS

One hundred and nine subjects participated in this research, 54 Malay men and 55 Malay women, aged 20-30 years old with healthy BMI and with no adverse skeletal deviation. Twenty-three facial landmarks were identified on 3D facial images captured using a VECTRA M5-360 Head System (Canfield Scientific Inc, USA). Two angular, 3 ratio and 17 linear measurements were identified using Canfield Mirror imaging software. Intra- and inter-examiner reliability tests were carried out using 10 randomly selected images, analyzed using the intra-class correlation coefficient (ICC). Multivariate analysis of variance (MANOVA) was carried out to investigate morphologic differences between genders.

RESULTS

ICC scores were generally good for both intra-examiner (range 0.827-0.987) and inter-examiner reliability (range 0.700-0.983) tests. Generally, all facial measurements were larger in men than women, except the facial profile angle which was larger in women. Clinically significant gender dimorphisms existed in biocular width, nose height, nasal bridge length, face height and lower face height values (mean difference > 3mm). Clinical significance was set at 3mm.

CONCLUSION

Facial soft tissue morphological values can be gathered efficiently and measured effectively from images captured by a non-invasive stereo-photogrammetry 3D camera. Adult men in Malaysia when compared to women had a wider distance between the eyes, a longer and more prominent nose and a longer face.

Dento-facial relationships in individuals with normal occlusion

The aim of this study was to evaluate the relationships of selected facial measurements with mesio-distal crown widths and dental arch dimensions in individuals with normal occlusions. A cross-sectional study was conducted on 276 subjects with Angle's Class I normal occlusions. Three-dimensional images of the face and dental casts were captured and analyzed using stereophotogrammetric systems. Significant correlations were found between the sagittal facial variables and both upper and lower dental arch dimensions and to lesser degree with the horizontal and vertical variables. The values of correlation coefficients calculated between facial and dental crown measurements ranged from .01 to .50 for upper teeth and .01 to .49 for lower teeth. The values of correlation coefficients between facial and upper dental arch dimensions ranged from .01 to .55 and those between facial and lower dental arch dimensions ranged from .01 to .60. A principal components analysis showed that the sagittal dimensions, face height, nose, labial fissure, binocular widths were positively associated with dental arch dimensions and mesio-distal crown diameters in males. On the other hand, only the sagittal variables were associated with dental dimensions in females. The results of this study confirm that positive associations exist between facial and dental arch dimensions. These relationships should be taken into consideration when attempts are made to modify dental arch size as part of orthodontic treatment. Moreover, these relationships are also relevant to prosthodontists involved with selecting tooth sizes that display optimal functional balance with the craniofacial structures.